Which... Muguruza is still incredibly frustrating to me. Like I'm not really a fan of hers so it doesn't bother me. But she should be much more of a consistent threat than she is.
Well Kerber didn't get going until she was 27 or 28. Muguruza has shown world beating, top tier talent since she showed up on tour. Beating Serena at the French, easily, 2 or 3 years before she won it.